Researchers at the University of Illinois at Urbana-Champaign and Dow Electronic Materials in Marlborough, Massachusetts has developed the new LED arrays that can be used in cell phones and other devices. These LED arrays charge themselves in ambient light and allow devices to be controlled with touchless gestures.

How do these LED arrays function?

These arrays are made of tiny nanorods each measuring less than 5 nanometres in diameter. LED arrays are made up of three types of semiconducting materials. One type emits and absorbs light and the other two controls the flow of charge through the first material. This facilitates LED arrays to respond, emit and sense the light.The display automatically adjusts the brightness on a pixel to pixel basis in response to light conditions and thereby maintains steady contrast. The researchers also demonstrated pixels that respond to brightness and pixels that respond to approaching finger and both can be integrated into to interactive displays that respond to touchless gestures or recognize objects. The researchers found that the LED arrays, a part of responding to light also possess the capability to generate electricity. The LED arrays in a way function as solar cells to harvest light for charging the phone without the need to integrate separate solar cells.

Moonsub Shim, a professor of materials science and engineering at the university of Illinois and the leader of the study, thinks that they can boost the power harvesting properties of the display without any effect on LED performance, so in a way power for display comes from array itself. These LED arrays interact with each other as large parallel communication arrays but it would be slower than device to device technologies like Bluetooth. So far the researchers have done the demonstrations using red LEDs and now they are working on methods to pattern three color displays with red, blue and green pixels. Alternately they are working on different methods to improve the light harvesting capacities of displays by changing the composition of nanorods.

Subscribe via email

About Sekhar MaddalaHave interests in multiple aspects and write articles on Technology, Lifestyle and Finance. Tracking developments since the launch of Nokia 1100 and completion of Human Genome Project